


The Magic of Arithmancy

by BelfastDocks



Category: Harry Potter - J. K. Rowling
Genre: Canon Compliant, F/M, Hogwarts Seventh Year, Homework, Horny Teenagers, Lime, Snowed In
Language: English
Status: Completed
Published: 2018-09-05
Updated: 2018-09-05
Packaged: 2019-07-07 08:22:02
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,530
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15904503
Author URL: https://archiveofourown.org/users/BelfastDocks/pseuds/BelfastDocks
Summary: Ron has never understood Hermione's love for Arithmancy, but a snowy morning at the Burrow changes his thoughts on the subject.





	The Magic of Arithmancy

**Author's Note:**

> Originally posted on the HP archive "Checkmated" years ago, 2008. I thought the archive had vanished, but it came back up for a bit and I decided to transfer the rest of my HP fanfiction to FFnet to save it. Now I'm in the process of transferring my works to AO3, which is what I should have done in the first place.
> 
> Thanks To: PigWithHair, who beta'd this story on Checkmated way back then.
> 
> Timeline: The Christmas after Harry Potter & The Deathly Hallows; Ginny and Hermione's 7th year at Hogwarts.
> 
> ~BD

****

## The Magic of Arithmancy

****

The last bit of Mrs. Weasley's cloak whipped out of sight into the emerald flames, and finally - _finally_ \- Ron was alone in the Burrow's warm kitchen. He smirked as the fire swirled orange again and lowered his hand; he had been waving good-bye to his family as they had left by the Floo Network just seconds prior. Thank _Merlin_ they were all gone at last.

But just the same, he waited a few minutes longer before the fire in case someone reappeared, claiming to have forgotten a scarf or mittens or a shopping list. The seconds slowly ticked by, but fortunately, no one clambered back out of the fire to ruin his morning.

Ron slowly exhaled.

Alone.

It was a powerful feeling that left his fingers tingling. It was intriguing and thrilling, a little naughty and somewhat wicked. Because somewhere upstairs, a certain, slightly-bushy-haired young woman was also _alone_. He and Hermione were alone together in this empty, cozy, crooked house, and no one was due back for at least two hours unless something unexpected happened. Ron's pulse quickened with excitement at the mere thought.

After all, when he'd hatched the half-cocked idea that morning, he hadn't really expected it to work. It was a hopeful thought, but at the same time, nothing more. With so many Weasleys, someone was bound to stay at the Burrow all day, especially with the several inches of snow on the ground outside. He'd only made the off-hand suggestion at breakfast that it would be a perfectly lovely day for his mother to do her Christmas shopping, since the snow was pretty and would enhance the holiday spirit, without really believing the plan would actually go as he'd dreamed.

Ginny, of course, had given him a bemused yet disgusted look that clearly indicated she knew _exactly_ what he was up to the moment the words left his mouth. But his mum didn't seem to be so quick to catch on.

"It _is_ pretty outside," she had conceded, patting her hair as she gazed through the kitchen window into the garden. "And I do still have a few gifts to buy."

As a result of this remark, Ron had hovered in the kitchen for nearly two hours while his mother cleaned the breakfast dishes and then went upstairs to change into a nicer robe. She somehow managed to coerce Ginny into accompanying her, and Ron could tell that Ginny was a trifle angry with very the idea of going to Diagon Alley. While his little sister fastened her cloak over her shoulders, she had scowled furiously at him, and he knew she wanted to stay behind just to wreck his plans. Probably because she wanted to be alone with Harry, he thought smugly. And Harry was helping Kingsley at the Ministry all day.

Once it was certain that her mother wanted her to go along, Ginny had switched tactics. Deliberately trying to thwart his plans, she attempted to convince Hermione to go to Diagon Alley as well. But Hermione stated that she would really rather stay behind, as she had already finished her Christmas shopping in Hogsmeade before the holiday break. Much to Ginny's dismay and annoyance, Hermione had retreated upstairs once breakfast was over.

And two hours later, when Mrs. Weasley finally reappeared in the kitchen, she was wearing a velvet crimson cloak and tugging soft, cream-colored mittens on her hands. She had announced that she and Ginny were off to London, but that Hermione was going to stay at the Burrow. She still didn't seem overly phased or even aware that she would be leaving her youngest son and his girlfriend alone, but Ron certainly didn't mention the fact or hint at what he had managed to get his mother to do. It never occurred to him that she might already know.

Instead, he did a quick mental check in his head while she searched for the pot of Floo Powder on the mantel.

His father was at work. Bill and Fleur were at Shell Cottage and wouldn't be arriving until Christmas Eve. Charlie wouldn't be in from Romania for another two days. Percy was at work, George was at work, and Harry was at work. Fred was still (despite Ron's wishing otherwise) dead, and it was likely that Auntie Muriel would stay shut up in her huge Victorian home for the entire holiday season, writing scathing letters to _Witch Weekly_ about how the Apple-Crumb Tart hadn't turned out exactly the way the recipe said it would.

Ron's pent-up desire could finally be released, and the thought enabled him to smile in a sickeningly sweet way at Ginny as she reluctantly climbed into the fireplace, shot him a look of deepest loathing, and snarled, "Diagon Alley!" Mrs. Weasley did the same afterwards, and Ron was thankful that Ginny had gone first - she would have lingered if his mum had been the first to leave.

And now, amazingly, after two hours, several scathing looks from his sister, and a full stomach, he was alone in the Burrow with Hermione.

He glanced up at the ceiling, his fingers itching to slide under the snug green jumper she had been wearing at breakfast. He gave the merry fire a final smirk and then bolted out of the kitchen with a sudden burst of energy, taking the first flight of stairs two at a time.

He stopped on the landing, his heart pounding wildly. His girlfriend was rooming with Ginny for the holidays, since so many people would be coming in over the next few days. The bedroom door was only partially shut, and he slowly pushed it open just a bit to peek inside.

Hermione was sitting at Ginny's desk, with her back to the door and her head bent over a long scroll of parchment that was trailing to the rug beneath her chair. She seemed quite absorbed in her work, but this didn't surprise Ron. One did not spend eight years in Hermione's presence without learning that parchment and books _absorbed_ her.

Ron stepped into the room, closing the door quietly behind him. He cast a silent _Colloportus_ charm just in case someone came home before he was done. Hermione's quill was still scratching across her parchment as he slipped his wand into his back pocket again and casually began to cross the room.

She realized he was there just as he started towards her; her quill suddenly paused upon the parchment. But then, after a moment, she started writing again.

Miffed at this lack of response, Ron glanced over her head at what she was writing and, involuntarily, he shuddered. He may have spent eight years with her, he thought with annoyance, and he might understand some things - like how she could get so absorbed in her studies or a good book - but he truly couldn't understand why she loved the difficult (or rather, as he and Harry felt, the _impossible_ ) subject of Arithmancy.

On the desk beside her parchment lay a gigantic number chart, complete with ruins, symbols, numbers, and letters. In fact, it was so large that there was no room on the desk for her Arithmancy book. The book was instead open on a chair beside her, and the page was full of a complicated theory about multi-number strengths in conjunction to spell casting, all written in such a tiny type font that Ron had to squint to make out the words.

He wrinkled his nose. Perhaps Fate was against him after all. He was finally alone in the Burrow with the girlfriend he hadn't seen but twice in four solid months, because she'd wanted to go back to school and finish her education, and she _still_ wanted to do schoolwork during the holidays.

He coughed slightly, trying to catch her attention. The quill paused, and Ron took it for a hopeful sign.

"Hermione, don't you think you can do that _after_ Christmas? You have days to finish it. I really think you should relax a little."

Hermione shrugged slightly, and to his irritation, she began writing again.

Without looking up, she said, "Not right now, Ron. This is complicated - I want to finish it and get it out of the way as quickly as possible. I'll lose my place if I stop."

He sighed inwardly. Getting Hermione away from her books was going to be a lot harder than he thought. He ruefully thought that he should have guessed _that_ when getting his huge family out of the house was so much easier than it should have been.

"Everyone's gone out shopping, or they're at work," he said, trying to sound off-hand, and not too eager. It was incredibly hard. He really wanted to get the sweater off of her body and see what kind of bra she was wearing. He hoped it was satiny and black, barely big enough to cover her. The very idea made his jeans feel at least a size too small in the crotch.

Hermione tucked her hair behind her ear and gazed at a sentence she had just written. "Yes, I knew your mum was going out. Ginny asked if I wanted to go, but I'm so glad I finished my shopping in Hogsmeade. I'm sure Diagon Alley will be packed with people today, rushing about and all. Christmas is only a week away."

Ron's eyes followed the way a curled strand of hair had fallen from behind her ear despite her efforts to keep it out of her way, and he mastered the impulse to keep his hands buried in his jean pockets. If he made a false move, like touching her hair (which he so wanted to do), she'd probably just get really annoyed with him and order him out of the room.

"So, what's this about?" he asked, keeping his voice casual as he glanced down at the Arithmancy book. He could _pretend_ to be interested, even if Arithmancy made no sense in the least to him, if it helped him get Hermione away from her studies and into his room for a while.

"Combined Number Theories," answered Hermione mechanically as she started to write again.

Ron paused, and the silence hovered thickly.

Did she really expect him to figure that one out on his own? He sighed once more and shifted his weight. Sometimes, Hermione's brilliance could make him feel really dumb. His only consolation was that Harry usually felt the exact same way.

He finally ventured, "Which means...?"

She glanced at the chart beside her once more, following x-axis four to y-axis twenty-nine. She made a note on the parchment of the ruin in the box where the two axes met before she said, "If you use certain magical numbers in your spell casting, your magic becomes stronger. So if you use combinations of magical numbers, the strength increases even more."

When Ron didn't reply right away, Hermione straightened and pulled her hair behind her neck, twisting it to keep it out of her way. "The theory is really very simple. Just tedious."

"It looks really hard."

She leaned back in the chair and surveyed him. Ron smiled blandly, hoping she wouldn't figure out that he really didn't give a Krup's arse about Arithmancy. He just wanted to get his hands under that snug jumper and unhook her bra, and then...

Instinctively, he clenched his fingers in his pockets to keep them from moving. Merlin, she was gorgeous. He could just envision what those tight, rosy nipples would look like once he freed them from the confines of clothing and the cool air hit them. Her long curls would dance over her soft, pale shoulders, and he'd slide his hands up and down her body slowly, savoring every inch...

"Well, for example," she began, gesturing with her hand, and not noticing the way his body had suddenly tensed or the way his eyes had glazed over from staring at her. "Take Voldemort's Horcruxes."

Instantly, Ron flinched and winced. _That_ was as good as a cold shower, he thought irritably. All thoughts of nipples, curls, and Hermione's gorgeous skin vanished from his brain. A year and a half later and he still hated hearing that dreadful word. He'd been so eager to snog with Hermione, and she had to go and bring up _Voldemort_ , of all bloody things. Not to mention that the very idea of Horcruxes, in particular the locket, still terrified him, even though he knew they were all completely destroyed.

"I'd rather not, thanks," he said sharply.

"What I _mean_ is," Hermione explained, "Voldemort intended to create seven Horcruxes. Seven is the most magical number. So by creating seven, he would have strengthened himself considerably. That's a very basic example," she admitted. "What I'm studying this year is the use of several magical numbers in conjunction with magic. Suppose you take seven and three, combined with the protection spell of -"

"I still think you should take a break," Ron suggested again. Once Hermione got going on a subject she loved passionately, it was impossible to stop her.

"Oh no, I couldn't possibly!" Hermione looked scandalized as she turned back to the parchment. "I'd lose my concentration entirely and then I'd have to start all over."

"Just fifteen minutes?"

"No, absolutely not..." She wrote another line of her essay. "I might be able to finish before lunch if I keep going."

" _Might_?" he asked anxiously. By lunch, his mum would be back, and Ginny would discover that Hermione had studied during the entire time that the Burrow had been void of Weasleys, minus Ron. He would be forced to endure an entire week or so of his sister's smirks and silent laughter, and he didn't think he could bear either. She might even tell Harry, who would also have a nice laugh at Ron's expense...or worse, she would tell _George_ , and Ron would _never_ live this day down.

Hermione followed another two axes on the grid. "Well, lunch is just an estimated timeframe. I'm really not sure how much longer it will take. It depends on how difficult the equations get."

Ron suddenly felt his temper rising, and before he could stop himself, he blurted, " _Bloody hell_ , Hermione! I haven't seen you in four months, except for a couple of Hogsmeade weekends when Harry and I met you and Ginny for the afternoon! You got here yesterday and you're _still_ doing schoolwork, and everyone's out of the house for a few hours! We could go upstairs and... and..." He raked his hands into his hair in frustration, finally freeing them from the jean pockets, and left the implication as was before barreling on, "But _no_ , you want to do _homework_!"

Hermione looked up from the essay once more and stared at him, and he knew instantly that he'd made the mistake he had been so desperately trying to avoid. Her face flushed a beautiful shade of pink, and her brown eyes glittered at him. "Go upstairs and _what_ , exactly?" she asked coolly.

"Get that blasted jumper off of you, for starters!"

"Well, as fun as _that_ sounds, I have to finish this!"

"It's just a bunch of numbers!" Ron argued. He knew he was treading on thin ice, but his patience was now non-existent.

"It is not!" Hermione cried. Her voice was hot and testy now. "It's extremely important! The theories apply to a lot of different fields of magic -"

"Well, at the moment, they aren't helping _me_ much!"

Hermione pursed her lips. There was a slight pause and before he could speak again she had grabbed her wand. Ron instinctively backed up a step, realizing that there was no way to repair the damage he'd wrought during the few seconds of exploding. When he and Hermione had a row, it was never good...but if she had her wand, he was doomed.

And he had been doing _so well_ before he lost his temper, he thought.

Hermione snapped, "For your information, they can help you a lot." She had stopped in front of him, but she hadn't cast a curse or hex yet.

He blinked, trying to figure out why she wasn't banishing him from the room.

"Take out your wand."

Merlin's _arse_ \- it was worse than being banished. He hadn't gone back to school, and a year without homework had been heaven. Now she was going to make him do homework _with_ her, on a subject he knew nothing about.

"Come on, Hermione - I don't know the first thing about Arithmancy..."

"Wand," she ordered sharply.

Sighing in resignation, Ron sadly took his wand from his back pocket. He wondered how many other blokes were punished by doing homework on a subject they'd never taken, just for wanting to get a bit randy with their girlfriend.

Hermione stepped up to him and, to his surprise, she linked their arms, holding her wand straight to the ceiling and forcing his to do the same. He hadn't been expecting the sudden movement or the connection, and his blood rushed to his groin once more. She was very close - he could smell the soft scent of her hair, like a strange combination of nutmeg and roses. He wasn't sure how long he could stand here casting odd spells with her, without dragging her to the floor and kissing her senseless.

"I'm going to recite a spell," she said importantly. "The first time I recite it, you're going to tell me seven memories you have of me from Hogwarts, from each of our seven years there."

"But we didn't go _our_ seventh year."

"Just use one from last year, when we were searching for Horcruxes, Ron."

"All right, all right..."

"Then, you're going to cast the same spell I did - so listen closely the first time I say it - and I'm going to say seven memories I have of you from each of our seven years at Hogwarts," she continued. "Then _we're_ going to cast the spell again, a third time, together."

Ron watched her with apprehension. "What's going to happen the third time?"

Hermione flushed. "If it works right, we'll be able to recite seven _more_ memories _together_. That won't be repeats of our first sets."

"You mean, at the same time?"

"Yes, at the same time. The spell is designed to strengthen relationships, whether friendship or otherwise, when cast in conjunction with the numbers seven and three - two of the most powerful magical numbers in the wizarding world. Of course, the theory in the text merely says to use seven memories spoken by the first person, then seven spoken by the second person, and the third set will be a result of mind melding. From the casting, I mean. The mind melding will create a special bond, based on the relationship."

"Mind melding?" Ron gaped at her. "That sounds dangerous, Hermione -"

"Well, yes, but in this case it's just an example. I think it'll be all right."

"You _think_ we'll be all right?" His voice rose slightly.

This was _not_ how the morning was supposed to go. Hermione was about to experiment in spell casting with him - why couldn't they just go up to his room for a while and snog? If his mother came back and discovered they had been reduced to melted blobs on the floor, she would set them straight only to bawl at Ron for being a barmy idiot.

"It's not going to kill you," Hermione complained.

"I didn't say it would -"

"If anything, it will strengthen our relationship! No one even uses these spells anymore because they're considered old-fashioned, and half-forgotten, but the theory remains the same!"

He paused. He had always thought that strengthening their relationship at this point in the game would mean a lot of exploring of each other's bodies - not casting bloody Arithmancy spells that may or may not go wrong.

Ron took a deep breath. "Wait, Hermione. These memories - do they have to be good or bad memories?"

"Whatever comes to your mind first," she said, her eyebrows raised.

"Okay." His voice felt dry. He was not ready for this at all and had no idea what to expect.

Hermione inched closer and tightened the link where their arms twisted. She touched the tip of her wand to his and murmured, " _Priori Amor Memoria_ ".

Nothing seemed to happen between the wands - there was no flash of light or dazzling burst - but Hermione looked expectedly at Ron, who cleared his throat nervously.

"Uh... That's it, then? Ah. Okay. Uh... first memory..."

He thought back to their first year at Hogwarts, trying desperately to remember something about Hermione. The train ride floated to his memory first, and he recalled bitterly how she had been so bossy and infuriating.

"You told me I had dirt on my nose on the Hogwarts Express. Second year..." His heart wrenched. "You were lying in the hospital wing petrified, and I couldn't do anything to help you. Third year... We were fighting about Crookshanks and Scabbers."

Merlin - he felt sulky remembering that. And the next memory was no better.

"Fourth year, you were Krum's person to get from the lake. Fifth year, you came up with the idea for Harry to teach Defense Against the Dark Arts to rebel against Umbridge. Sixth year..." He swallowed hard. "You nailed me with those bloody birds after the first Quidditch match. Seventh year... Well, while we were roaming all over the place... You sure did try to attack me when I returned," he said, smiling fondly at the memory of how Hermione had gone ballistic on him when he'd entered the tent, soaking wet and freezing, with Harry and the Sword of Gryffindor. He'd never thought she had such a temper, but it had been comforting, in a weird way, to see her so deranged and insane. It made sense in a situation where nothing else made sense.

He quickly forgot about the memory, however. To his surprise, when he finished, a bright orange thread of light twisted around their wands and their hands. It was warm and tingly. He almost yelped, but Hermione looked at him calmly and nodded her head to remind him it was his turn to recite the spell.

Ron shifted uneasily and focused on his wand, trying to remember what she had said. Then nervously, he mumbled, " _Priori Amor Memoria_."

Hermione said calmly, "First year, you saved my life by fighting the troll in the bathroom. Second year, you went into the Chamber of Secrets to help Harry kill the Basilisk. Third year, you tried to fight Sirius in the Shrieking Shack even though your leg was broken. Fourth year, we got into a huge fight after the Yule Ball. Fifth year, you were made Prefect with me. Sixth year, you nearly died from poisoning and I was so worried you wouldn't make it. Seventh year, you kept screaming my name while we were at Malfoy Manor and Bellatrix Lestrange was torturing me. It was the only thing that kept me from just...dying."

A surge of heat rushed through his body. The memory of Hermione's torture was as painful and fresh as the night it had happened, but he had saved her life in the end, and to hear her say that his voice had kept her from succumbing to death made him feel proud and special and important - that he was truly all hers. But he had little time to feel the onslaught of emotion; when she finished, a thread of bright brown light came from the tip of her wand and twisted around Ron's thread of orange. He looked at her, and she nodded.

Together, they said, " _Priori Amor Memoria_."

Instantly, it was as though Ron's mind were hearing things he hadn't been thinking...or maybe he was thinking them. When he looked at her Hermione, he realized she was thinking the exact same things. The sensation was incredibly odd, but he felt as though he were floating.

It was utterly amazing.

Together, they said, "First year... Gryffindor won the House Cup at the end of the year because we saved the Philosopher's Stone." Their voices were in almost perfect unison, and Ron grinned sheepishly as Hermione smiled gently at him. The threads of light on their wands begin to twist together. "Second year..."

"Malfoy called you a Mudblood..." Ron started, gazing at Hermione.

"...and you tried to defend me," Hermione completed, gazing back at him. The orange and brown threads twisted closer and started to meld.

"Third year... We saved Sirius and Buckbeak... Fourth year..."

"I," Ron said.

"You," Hermione echoed.

"Realized you," Ron murmured.

"Realized I," Hermione breathed.

"Were a girl," they said together.

"Fifth year... We fought the Death Eaters in the Department of Mysteries together. Sixth year..."

"I held you," Ron said, gazing in her eyes and seeing Dumbledore's funeral in his head. The emotion of overwhelming sadness filled his heart as he remembered Hermione's tears and the marble tomb with its bright flames and how wretched he had felt that day.

"At the funeral," said Hermione, her voice slightly thick.

"Seventh year..." Their voices were together again. "We kissed for the first time."

The orange and brown threads had turned bright white by the end of their recitation, and for a long moment Ron and Hermione stared at each other. Then slowly, Hermione broke the connection between their wands, and the light died away.

Ron stood before her, his ears buzzing strangely. It had been the weirdest feeling, reading Hermione's mind, knowing what she was going to say next and recalling those memories that he had pushed to the back of his mind. He still felt connected to her, as if by the magic they had just cast.

After a long moment, he said hoarsely, "Wow."

Hermione's breathing was shallow. "That _was_ pretty amazing, wasn't it?"

"And you did all that with Arithmancy?" he asked in awe.

She laughed - a beautiful sound that made his knees buckle.

"Yes, Ron. It was a very basic example, but yes. And speaking of Arithmancy, can I please finish my assignment? I really must."

"Hermione, do you really _have_ to? No one's home right now, and it's been so long since I've seen you... I've _missed_ you. And after all _that_..."

Hermione glanced at the parchment on the desk and bit her lower lip, obviously contemplating her options. Ron reached out and took her arm and gently pulled her towards him. She stumbled into his chest and looked up at him with wide eyes.

After a moment she whispered, "Well... maybe I can finish it after lunch instead..."

Ron grinned at her as the blood rushed through his body triumphantly. His hands _finally_ slipped beneath the jumper where they had wanted to be for over two hours now. Hermione's soft, warm skin greeted his eager fingertips, and a low moan escaped her throat that made him feel powerful and possessive. They belonged together. He dipped his head and began to trail kisses down her neck, inhaling the scent that was so uniquely Hermione.

Perhaps Arithmancy had its uses after all, he thought vaguely.

**~FIN~**


End file.
